Distribution of Chemical Carcinogens in Aquatic Environments

AbstractThe purpose of this paper is to report on an expert system in design that screens for potential hazards from environmental chemicals on the basis of structure-activity relationships in the study of chemical carcinogenesis, particularly with respect to analyzing the current state of known structural information about chemical carcinogens and predicting the possible carcinogenicity of untested chemicals. The structure-activity tree serves as an index of known chemical structure features associated with carcinogenic activity. The basic units of the tree are the principal recognized classes of chemical carcinogens that are subdivided into subclasses known as nodes according to specific structural features that may reflect differences in carcinogenic potential among chemicals in the class. An analysis of a computerized data base of known carcinogens (knowledge base) is proposed using the structure-activity tree in order to test the validity of the tree as a classification scheme (inference engine).

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Contributions of anoxygenic and oxygenic phototrophy and chemolithotrophy to carbon and oxygen fluxes in aquatic environments

Aquatic Biology ◽

10.3354/ab01315 ◽

2009 ◽

Cited By ~ 1

Author(s):

JA Raven

Keyword(s):

Aquatic Environments

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Structural description of sea turtle fibropapilloma

Brazilian Journal of Veterinary Pathology ◽

10.24070/bjvp.1983-0246.v13i3p585-591 ◽

2020 ◽

Vol 13 (3) ◽

pp. 585-591

Author(s):

Luana Melo ◽

Isabel Velasco ◽

Julia Aquino ◽

Rosangela Rodrigues ◽

Edris Lopes ◽

...

Keyword(s):

Green Turtle ◽

Chelonia Mydas ◽

Sea Turtle ◽

Tumor Formation ◽

Neoplastic Disease ◽

Structural Description ◽

Chemical Carcinogens ◽

Epidermal Proliferation ◽

Turtle Population ◽

Bulky Mass

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.

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